How to realize DMA in PCI-6251 with VC++.NET?

[David_Lin]

I was using another DAQ card and now I have to change to PCI-6251 for a new project. I have to use VC++.NET to write my own application for data sampling and manipulating. I have gone throught the 3CDs coming with the card, searched for a long time in the NI website, and finally failed to find the function reference or any articles on it. Would anyone tell me where to find the function reference or sample code using the DMA for PCI-6251? Thanks a lot!

[Hal_L]

Hi,

The Visual C++ examples for DotNet are located in C:\Program Files\National Instruments\NI-DAQ\Examples\DAQmx ANSI C. The PCI-6251 uses DMA as its data transfer mechanism by default so these examples will use DMA. There are functions that can manually set the data transfer method. You can find these functions by searching for "DMA" in the NI-DAQmx C Reference Help. This is located in Start >> All Programs >> National Instruments >> NI-DAQ >> NI-DAQmx C Reference Help. This help file also has information on all of the DAQmx C functions. I hope this information helps you with your new project.

Regards,
Hal L.